Update app.py

app.py

@@ -127,6 +127,10 @@ def init_agent():
 
 
 def stream_final_report(agent, file) -> Generator[Union[Dict[str, str], Tuple[List[Dict[str, str]], str]], None, None]:
+    if file is None or not hasattr(file, "name"):
+        yield {"role": "assistant", "content": "❌ Please upload a valid Excel file before analyzing."}
+        return
+
     extracted_text = extract_text_from_excel(file.name)
     chunks = split_text_into_chunks(extracted_text)
     chunk_responses = []
@@ -191,7 +195,7 @@ def create_ui(agent):
         report_output = gr.File(label="Download Report")
 
         analyze_btn.click(
-            fn=stream_final_report,
+            fn=lambda file: stream_final_report(agent, file),
             inputs=[file_upload],
             outputs=[chatbot, report_output]
         )